1. Field of the Invention
The present invention pertains to the art of cooking appliances and, more particularly, to a convection oven incorporating an open coil heating element arranged in an air flow path for the oven.
2. Discussion of the Prior Art
It is known in the art to utilize open coil heating elements to heat oven cavities. In general, multiple heating elements are provided within a single oven cavity for use in connection with baking, broiling and/or cleaning modes of operation. It has also been proposed in the art to incorporate a fan within the oven cavity to enhance the flow of heated air in order to provide for a more uniform temperature distribution within the oven.
Regardless of these known prior art arrangements, there exists a need for further enhancements in the heating of the air flow for a convection oven. More specifically, there exists a need in the art of cooking appliances for a convection oven arrangement with enhanced pre-heat capabilities. In addition, there exists a need for a convection oven heating arrangement which minimizes non-linear air flow patterns so as to optimize the overall heating characteristics of the system.
In accordance with the invention, a convection cooking appliance is provided with multiple heating units, with at least one being constituted by an open coil heating unit disposed outside an oven cavity of the cooking appliance. More particularly, the heating unit is disposed in an upper duct section of an air channel assembly which extends about and is in fluid communication with the oven cavity. A flow of air is directed through the channel assembly by a blower. In the most preferred form of the invention, the heating unit is centered in the air flow stream and arranged continuous from side-to-side. The heating unit preferably defines a single coil extending in various rows, with each of the coil rows being arranged substantially perpendicular to the flow of air. With this configuration, the heating unit tends to interrupt any developing patterns of air flow other than a linear flow in a desired direction.
Another heating unit of the system is positioned within the air flow assembly, while a third heating unit is arranged within the oven cavity. In addition, a microwave generator is provided, preferably below the oven cavity. Furthermore, a catalyst is located in the air channel assembly upstream of the blower. A controller is provided to regulate the activation and deactivation of each of the heating units, as well as the blower and the microwave generator, based on operator inputs and signals received from a temperature sensor to enable the cooking appliance to be operated efficiently in various cooking modes.
Additional objects, features and advantages of the present invention will become readily apparent from the following detailed description of a preferred embodiment thereof, when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.